Intervertebral implant

ABSTRACT

Implants for positioning between vertebral members. The implant may include a superior surface to contact against a first vertebral member, and an inferior surface to contact against a second vertebral member. The implant may include a central web that extends between first and second flanges. The flanges may be shaped to form gaps that extend the height of the implant. Spaces in communication with the gaps may be formed in an interior of the implant to hold bone growth material.

BACKGROUND

The present application relates generally to vertebral implants andmethods of use, and more particularly to implants that include gapsaround a periphery of the implant body.

The spine is divided into four regions comprising the cervical,thoracic, lumbar, and sacrococcygeal regions. The cervical regionincludes the top seven vertebral members identified as C1-C7. Thethoracic region includes the next twelve vertebral members identified asT1-T12. The lumbar region includes five vertebral members L1-L5. Thesacrococcygeal region includes nine fused vertebral members that formthe sacrum and the coccyx. The vertebral members of the spine arealigned in a curved configuration that includes a cervical curve,thoracic curve, and lumbosacral curve. Intervertebral discs arepositioned between the vertebral members and permit flexion, extension,lateral bending, and rotation.

Various conditions may lead to damage of the intervertebral discs and/orthe vertebral members. The damage may result from a variety of causesincluding a specific event such as trauma, a degenerative condition, atumor, or infection. Damage to the intervertebral discs and vertebralmembers can lead to pain, neurological deficit, and/or loss of motion.

Various procedures include replacing the entirety or a section of avertebral member, the entirety or a section of an intervertebral disc,or both. One or more replacement implants may be inserted to replace thedamaged vertebral members and/or discs. The implants may further includebone growth material to facilitate fusion of the implant to one or bothadjacent vertebral members.

SUMMARY

The present application is directed to implants that fit within anintervertebral space formed between first and second vertebral members.The implant may include a body with a central web and first and secondoutwardly-extending flanges. The first and second flanges may be spacedapart along the central web. The body may include an exterior surfaceformed by one or more of the central web and the flanges. The body mayfurther include a height defined by a superior surface that contacts thefirst vertebral member and an inferior surface that contacts the secondvertebral member. First and second spaces may be formed within aninterior of the exterior surface and may extend the height of the body.A first gap may be formed in the exterior surface on a first side of thecentral web, and the first gap may be in communication with the firstspace and extend. A second gap may be formed in the exterior surface ona second side of the central web. The second gap may be in communicationwith the second space and extend the height of the body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a implant according to one embodiment;

FIGS. 2-10 are top views of implants according to various embodiments.

FIG. 11 is a side view of an implant according to one embodiment.

FIG. 12 is a side view of an implant according to one embodiment.

FIG. 13 is a side view of an implant according to one embodiment.

FIG. 14 is a side view of an implant according to one embodiment.

FIG. 15 is a side view of a mount according to one embodiment.

FIG. 16 is a perspective view of a cover according to one embodiment.

FIG. 17 is a top view of an implant with a cover according to oneembodiment.

FIG. 18 is a perspective view of an implant with a cover according toone embodiment.

DETAILED DESCRIPTION

The present application is directed to implants for positioning withinan intervertebral space formed between first and second vertebralmembers. FIG. 1 illustrates one embodiment of an implant 10 with asuperior surface 91 to contact against a first vertebral member, and aninferior surface 92 to contact against a second vertebral member. Theimplant 10 includes a central web 20 that extends between first andsecond flanges 30, 40. The flanges 30, 40 are shaped to form gaps 50that extend the height of the implant 10. Spaces 51, 52 in communicationwith the gaps 50 are formed in an interior of the implant 10 to holdbone growth material.

The web 20 extends between the flanges 30, 40 and forms a centralsection of the implant 10. Web 20 may include a variety of shapes andsizes. FIGS. 1 and 2 include the web 20 with a substantially constantwidth, with FIG. 3 including a web 20 with a variable width. The web 20of FIG. 3 reduces to a neck 26 at an intermediate point between theflanges 30, 40. The width increases on each side of the neck 26 with thewidth being larger at the second flange 40 than at the first flange 30.

Web 20 may also include multiple different sections. FIG. 4 illustratesan embodiment with the web 20 formed by multiple sections 21, 22, 23that are spaced apart with spaces 24 formed therebetween. The multiplesections 21, 22, 23 and spaces 24 may include the same or differentshapes and sizes. FIG. 5 illustrates another embodiment including a web20 with a brace 25 branching off and connecting with the first flange30. In another embodiment, web 20 is constructed of a single sectionthat includes an aperture that extends between the superior and inferiorsurfaces 91, 92.

Web 20 may further be positioned at various lateral locations within thecentral section of the implant 10. FIGS. 1 and 2 illustrate anembodiment with the web 20 laterally centered within the implant 10 andpositioned at a middle of each of the flanges 30, 40. In otherembodiments as illustrated in FIG. 5, the web 20 is laterally offsetaway from a center of the implant 10. In some embodiments as illustratedin FIGS. 1, 2, and 5, the web 20 is laterally spaced the same distancealong the first and second flanges 30, 40. Alternatively as illustratedin FIG. 6, the web 20 is spaced at laterally different positions alongthe first and second flanges 30, 40.

The first and second flanges 30, 40 are space apart along the web 20.The flanges 30, 40 may be the same shape and size, or may includedifferent shapes and sizes. FIG. 7 includes an embodiment with each ofthe flanges 30, 40 being the same shape and size. FIG. 2 is anembodiment with the first flange 30 including a different shape than thesecond flange 40. FIG. 8 includes an embodiment with the flanges 30, 40including different shapes and sizes.

As illustrated in FIG. 2, the first flange 30 may include a first arm 31that extends outward from a first side of the web 20, and a second arm32 that extends outward from a second side of the web 20. Each arm 31,32 includes an end 33 that forms a side of a gap 50. The arms 31, 32 mayinclude the same shape and size as illustrated in FIG. 2, or may includedifferent shapes and/or sizes as illustrated in FIGS. 5 and 6. Likewise,the second flange 40 may include first and second arms 41, 42 asillustrated in FIG. 2. Each arm 41, 42 includes an end 43 that forms aside of a gap 50. Arms 41, 42 may include the same or different shapesand/or sizes.

In one embodiment, one of the flanges 30, 40 includes a single arm. FIG.8 illustrates an embodiment with the first flange 30 including a singlearm 31. The first gap 50a is formed between an end 33 of the single arm31 and end 43 of arm 41. The second gap 50b is formed between the web 20and the end 43 of arm 42. In one embodiment as illustrated in FIG. 9,the implant 10 includes a single flange 30 (i.e., there is no secondflange 40). Each gap 50 is formed between arm ends 33 and the web 20.

In one embodiment as illustrated in FIG. 10, one or both of the flanges30, 40 include ends 34, 44 with enlarged widths. The enlarged ends 34,44 are adjacent to the gaps 50. The enlarged ends 34, 44 include alarger surface area adjacent to the gaps 50 to distribute the forcesapplied to the implant 10 from the first and second vertebral membersand alleviate specific stresses from occurring at the ends 33, 43 of theflanges 30, 40.

As illustrated in FIG. 11, the implant 10 includes a height H measuredbetween the superior surface 91 and the inferior surface 92. In oneembodiment, the height H is substantially the same across the implant10. In other embodiments, the height H may vary across the implant. FIG.12 illustrates an embodiment with a portion of the first flange 30including a smaller height H′. This smaller height facilitates insertionof the implant 10 between the vertebral members with the section withthe smaller height H′ being initially inserted into the intervertebralspace. Various other sections of the implant 10 may include larger orsmaller heights depending upon the context of use.

The gaps 50 extend the height H of the implant 10 between the superiorand inferior surfaces 91, 92. In one embodiment, the gaps 50 are formedbetween the arm ends 33, 43 on opposing sides of the web 20. In oneembodiment, the gaps 50 are formed between the arm ends 33, 43. In otherembodiments, the gaps 50 are formed by an arm end 33 or 43, and the web20. FIG. 9 includes an embodiment with each of the gaps 50a, 50b formedbetween ends 33 of the arms 31, 32 and the web 20.

The gaps 50 may include the same or different widths W. FIG. 2 includeseach of the gaps 50 with the same width W. FIG. 8 includes a first gap50a including a width W1 that is larger than the width W2 of the secondgap 50b.

The widths W of the gaps 50 may be constant or may vary along theheight. FIG. 11 includes an embodiment with the width W being constantalong the height H between the superior and inferior surfaces 91, 92.FIG. 13 includes an embodiment with a variable width with the end 33 ofthe first flange 30 being straight and the end 43 of the second flange40 including a curved shape. The ends 33, 43 cause the width W to belarger in the middle of the gap 50 than at the outer ends at thesuperior and inferior surfaces 91, 92. FIG. 14 includes an embodimentwith the gap 50 formed between the first flange 30 and the web 20. Thewidth W is smallest at the superior surface 91 and largest at theinferior surface 92.

Interior spaces 51, 52 are in communication with the gaps 50 andfunction to contain bone growth material. The spaces are bounded on thelateral sides and are unbounded on the superior and inferior sides. Thespaces 51, 52 may include the same or different shapes and sizes. FIG. 2includes one embodiment with each of the spaces 51, 52 including thesame shape and size. Space 51 is positioned inward from the gap 50a andis bounded by the inner edges of arm 31, arm 41, and web 20. Space 52 ispositioned inward from gap 50b and is bounded by the inner edges of arm32, arm 42, and web 20. FIG. 5 includes an embodiment with space 51being smaller than space 52.

A plate 80 may be formed on a lateral side of the implant 10. The plate80 may be a separate piece that is attached to the implant, or it may beintegrally formed with the body (i.e., the body plate 80 includes aunitary construction). Mount 80 extends above one or both of thesuperior and inferior surfaces 91, 92 to contact against the lateralsides of the vertebral members to maintain the implant 10 positionedwithin the intervertebral space. Mount 80 also prevents the implant 10from being over-inserted into the intervertebral space. One or moreapertures 81 may extend through the mount 80. Apertures 81 are sized toreceive fasteners (not illustrated) to attach the implant 10 to thevertebral members. In one embodiment as illustrated in FIG. 15,apertures 81a are positioned at a central height of the mount 80 andangle upward towards the superior surface 91 for engaging the fastenerswith the first vertebral member. Apertures 81b are angled downwardtowards the inferior surface 92 to engage the second vertebral member.In one embodiment, as illustrated in FIG. 15, the plate 80 extendsacross the entire body. In another embodiment as illustrated in FIG. 12,the plate 80 extends across a portion of the body.

The apertures 81 may extend through the plate 80 and into one of theflanges 30, 40 and/or the web 20. FIG. 7 illustrates one embodiment withthe aperture 81 extending through the flange 40 and into the web 20.FIG. 2 illustrates an embodiment with the apertures 81 extending throughthe flange 40 and into the spaces 51, 52 respectively.

Teeth 75 may be positioned on one or both of the superior and inferiorsurfaces 91, 92. Teeth 75 may include an angled orientation tofacilitate insertion of the implant 10 into the intervertebral space,and maintain the proper positioning within the space. Teeth 75 mayextend across an entirety or limited sections of the inferior andsuperior surfaces 91, 92. Embodiments of teeth for an intervertebralimplant are disclosed in U.S. patent application Ser. Nos. 11/394,452and 11/412,330 that are each herein incorporated by reference.

A cover 60 may be attached to the implant 10 to extend across one ormore of the gaps 50. FIG. 16 illustrates one embodiment of the cover 60that includes a first section 63 with opposing, spaced-apart arms 61,62. The cover 60 functions to extend across one or more of the gaps 50and prevent inadvertent lateral removal of the bone growth materialwithin the spaces 51, 52.

In one embodiment, arms 61, 62 are connected to the first section 63 tobe moveable in the directions of arrow Z. This may be caused by thecover 60 being constructed of an elastic material. The cover 60 is sizedto deform when inserted onto the spacer 10 with the arms 61, 62expanding outward. Once attached, the arms 61, 62 apply a compressiveforce to the exterior lateral sides of the implant 10 to maintainattachment of the cover 60. Apertures 64 may further be spaced about thecover 60 and sized to receive fasteners to further attach the cover 60to the implant 10.

In another embodiment, arms 61, 62 are movably connected to the firstsection 63 such as by hinges, pivots, or other like structure. The arms61, 62 may move apart during attachment of the cover to allow the arms61, 62 to extend along each side of the implant 10. Once positioned, thearms 61, 62 may move inward to contact against the exterior lateralsides of the implant 10. Apertures 64 may further be positioned aroundthe cover 60 to receive fasteners to attach the cover 60 to the implant10.

In use, the implant 10 is initially inserted into the intervertebralspace. Prior to insertion or after insertion, bone growth material isinserted into the spaces 51, 52. The cover 60 is then attached to theexterior lateral sides of the implant 10. The cover 60 may extend acrossone or more of the gaps 50 to maintain the bone growth material.

FIG. 17 includes one embodiment with the cover 60 attached to theimplant 10. The first section 63 includes a shape to substantially matchthe second flange 40. Arms 61, 62 substantially match the shape of thesecond flange 40, and include a length to extend across the gaps 50 andcontact against the first flange 30. Cover 60 may also be positionedagainst the mount 80 and extend over the apertures 81 to preventback-out of the fasteners. FIG. 18 includes an embodiment with a singlearm 61 extending outward from the first section 63. The arm 61 extendsacross the first gap 50a. In this embodiment, arm 61 includes a smallerheight than the gap 50a.

Cover 60 may also be attached to the implant 10 in other manners In oneembodiment, implant 10 includes notches along the exterior lateral sideand the cover 60 includes outwardly-extending fingers. Duringattachment, the fingers slide across the exterior lateral side and mountwithin one of the notches to maintain the attachment. Other attachmentsmay include snap fits and press fits.

The implant 10 may be inserted into the intervertebral space from avariety of directions. In one embodiment, the implant 10 is inserted inan anterior approach with the mount 80 contacting against the anteriorlateral sides of the vertebral members. Other applications contemplateother approaches, including posterior, postero-lateral, antero-lateraland lateral approaches to the spine, and accessing other regions of thespine, including the cervical, thoracic, lumbar and/or sacral portionsof the spine.

Spatially relative terms such as “under”, “below”, “lower”, “over”,“upper”, and the like, are used for ease of description to explain thepositioning of one element relative to a second element. These terms areintended to encompass different orientations of the device in additionto different orientations than those depicted in the figures. Further,terms such as “first”, “second”, and the like, are also used to describevarious elements, regions, sections, etc and are also not intended to belimiting. Like terms refer to like elements throughout the description.

As used herein, the terms “having”, “containing”, “including”,“comprising” and the like are open ended terms that indicate thepresence of stated elements or features, but do not preclude additionalelements or features. The articles “a”, “an” and “the” are intended toinclude the plural as well as the singular, unless the context clearlyindicates otherwise.

The present invention may be carried out in other specific ways thanthose herein set forth without departing from the scope and essentialcharacteristics of the invention. The present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

What is claimed is:
 1. An implant to fit within an intervertebral spaceformed between first and second vertebral members, the implantcomprising: a body including a web, a first pair of arms extendingoutward from a first side of the web, and a second pair of armsextending outward from a second side of the web, the body including aheight defined by a superior surface configured to contact the firstvertebral member and an inferior surface configured to contact thesecond vertebral member; a first gap formed between ends of the firstpair of arms and a second gap formed between ends of the second pair ofarms, each of the gaps extending the height of the body; and a coverthat attaches to an exterior lateral side of the body and extends acrossone of the first and second gaps, the cover including a first sectionthat extends along the body and a first arm that extends along the oneof the first and second gaps, the first arm of the cover having asmaller height than the height of the body.
 2. The implant of claim 1,further comprising a first space in communication with the first gap andbeing bounded on lateral sides by the web and the first pair of arms,and a second space in communication with the second gap and beingbounded on the lateral sides by the web and the second pair of arms,each of the first and second spaces being unbounded on superior andinferior sides.
 3. The implant of claim 2, further comprising anaperture that extends through the height of the web.
 4. The implant ofclaim 1, wherein at least one of the first and second gaps includes aconstant width along the height.
 5. The implant of claim 1, wherein thebody includes a symmetrical shape.
 6. An implant to fit within anintervertebral space formed between first and second vertebral members,the implant comprising: an elongated web with first and second ends; anda first flange positioned at the first end of the web and a secondflange positioned at the second end of the web, each of the flangesincluding a first arm extending outward from a first side of the web anda second arm from a second side of the web; each of the flangesincluding a height defined by a superior surface configured to contactthe first vertebral member and an inferior surface configured to contactthe second vertebral member; the first arms including ends that arespaced apart to form a first gap therebetween on a first side of the weband the second arms including ends that are spaced apart to form asecond gap therebetween on a second side of the web, each of the gapsextending the height of the flanges; a cover with a first section thatextends along one of the first and second flanges and a single extensionthat extends outward from the first section and across just the firstgap and terminates along the other of the first and second flanges awayfrom the first section, wherein the extension includes a smaller heightthan the height of the flanges to be positioned inward from the superiorand inferior surfaces when the cover is attached to the flanges.
 7. Theimplant of claim 6, wherein at least one of the gaps includes a constantwidth.
 8. The implant of claim 6, further comprising a first spacepositioned on the first side of the web and being bounded on lateralsides by the web and the first arms and being unbounded on inferior andsuperior sides, and a second space positioned on the second side of theweb and being bounded on the lateral sides by the web and the secondarms and being unbounded on the inferior and superior sides, the firstspace being in communication with the first gap and the second spacebeing in communication with the second gap.
 9. The implant of claim 6,wherein the web is positioned at a middle of the first and secondflanges.
 10. The implant of claim 6, wherein the web and the first andsecond flanges form a symmetric body.
 11. The implant of claim 6,further comprising a mount positioned on a lateral side of one of thefirst and second flanges, the mount extending outward beyond thesuperior and inferior surfaces.
 12. The implant of claim 6, wherein theweb includes a constant width.
 13. The implant of claim 6, wherein eachof the first and second flanges includes a curved shape.
 14. An implantto fit within an intervertebral space formed between first and secondvertebral members, the implant comprising: a body including a superiorsurface to contact the first vertebral member and an inferior surface tocontact the second vertebral member, the body including a web and afirst pair of arms extending outward from a first side of the web and asecond pair of arms extending outward from a second side of the web,each of the arms including an end extending between the inferior andsuperior surfaces, a height of the web being substantially constantalong the length with the superior surface of the web being aligned withthe superior surface of the first and second pairs of arms and theinferior surface of the web being aligned with the inferior surface ofthe first and second pairs of arms; a first gap formed between the endsof the first pair of arms and a second gap formed between the ends ofthe second pair of arms; a first space in communication with the firstgap and bounded on lateral sides by the web and the first pair of arms,the ends of the first pair of arms being in closer proximity than aremainder of the first pair of arms with a width measured between thefirst pair of arms being smallest at the first gap and largest withinthe first space; a second space in communication with the second gap andbounded on the lateral sides by the web and the second pair of arms; anda cover with a first section that extends along one of the arms of thefirst pair of arms and a single extension that extends outward from thefirst section and across just the first gap and terminates along theother arm of the first pair of arms away from the first section, whereinthe extension includes a smaller height than a height of the arms suchthat it is positioned inward from the superior and inferior surfaceswhen the cover is attached to the arms, upon insertion of the implantinto the intervertebral space, the gaps and spaces being unbounded onsuperior and inferior sides.
 15. The implant of claim 14, wherein thewidth of the first gap is equal to a width of the second gap.
 16. Theimplant of claim 14, wherein at least one of the gaps includes avariable width.
 17. The implant of claim 14, wherein the cover attachesto an exterior lateral side of the body and extends across at least oneof the gaps.
 18. An implant to fit within an intervertebral space formedbetween first and second vertebral members, the implant comprising: abody including a central member and first and second flanges extendingoutward from the central member, the first and second flanges beingspaced apart along the central member, the body including an exteriorsurface formed by one or more of the central member, the first flange,and the second flange, the body further including a height defined by asuperior surface configured to contact the first vertebral member and aninferior surface configured to contact the second vertebral member, theheight of a first end of the central member being equal to the firstflange and the height of a second end of the central member being equalto the second flange such that the central member is sized to contactthe first and second vertebral members at multiple locations across thelength of the central member between the first and second flanges; firstand second spaces each formed inward from the exterior surface andextending the height of the body, each of the first and second spacesbeing partially bounded by the central member; a first gap on a firstside of the central member, the first gap being in communication withthe first space and extending the height of the body; and a second gapon a second side of the central member, the second gap being incommunication with the second space and extending the height of thebody; a first distance between the first and second flanges on the firstside of the central member being smallest at the first gap and a seconddistance between the first and second flanges on the second side of thecentral member being smallest at the second gap; a cover with a firstsection that extends along one of the first and second flanges and asingle extension that extends outward from the first section and acrossjust the first gap and terminates along the other of the first andsecond flanges away from the first section, wherein the extensionincludes a smaller height than the height of the flanges to bepositioned inward from the superior and inferior surfaces when the coveris attached to the flanges.